A "Intake" is a inward scream used in death metal and hardcore bands such as Bring Me The Horizon and Suicide Silence. Another word for a "Intake" is a "pig squeal" because you're supossed to sound like a pig when performing the intake.

Setting- 2 guys at a Annotations of an Autopsy concert
1st guy: dude what kind of singing is that it sounds like a pig!?